John fish



(No Model.)

J. FISH.

Back Acting Steam Engine. No. 242,908' Pat ented June 14,1881.

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I UNITED I STATES PATENT OFFICE.

JOHN rise, or SUMMIT, NEW JERSEY.

BACK-ACTING STEAM- ENGINE.

SPECIFICATION forming part ofLetters Patent No. 242,908, dated June 14 1881, Application filed January 15,1881. (Il'o model.)

To all whom it may concern-.1

Be it known that 1, JOHN FISH, of Summit, in the county of Union and State of New J ersey, have invented a new and useful Improvement in Steam-Engines, of which the following is a specification.

My invention relates to improvements in that class of engines where the motion is transmitted from the piston-rod cross-head near one end of the cylinder to the crank-shaft placed near the other end of the cylinder.

The object of my improvements are, first, to form the crank in such a manner that the distance between the crank cheeks or throws is such as to allow the piston with its rod to pass between the throws or checks of the crank when it is necessary to withdraw it from the cylinder; second, the arrangement and construction of a connectingrod formed of side bars attached to a single pin at one end for the cross-head, and to a single crank-pin box extending the whole length of the crank-pin at the other end, whose cheeks or throws are wide enough apart to allow the piston to pass through them.

The advantages I obtain by this construction and plan of engine and arrangement of parts are these: Where two or more cylinders and their piston-rods are connected in line, and the motion given to the crank is taken from a cross-head between them, or from the crosshead where there is only'one cylinder, access 'to the piston cannot be had without disturbing the intermediate parts, unless the cylinders are bolted onto an independent frame or bed-plate at the cross-head end of the cylinder. In my plan there is no bed-plate or frame required, and if access to the piston is sought at the other end of the cylinder, as they are now constructed, the crank-shaft obstructs the way, so that it has to be removed before the piston can be examined or removed from the cylinder.

It has been the usual practice in back-actin g engines to transmit the motion from the crosshead to the crank-shaft by means of two side rods to two crank or disk wheels, each wheel having its own crank-pin. A fatal objection to this practice, more especially where high speed is required, is that the rods cannot be kept at the same length, as the journal-boxes wear, and the slack is taken up. Consequently a side strain is thrown upon the cross-head, and the friction and strain upon the engine are dangerously increased. Forked connectingrods have also been used to transmit motion from a cross-headof a back-acting engine, but always with a box upon the crank-pin so short as to prevent the piston from being removed from the cylinder without disturbing the shaft, and the cross-head ends of the rod had each separate boxes, producing the same evils that exist with two separate rods.

It will be observed, by referring to thedrawings attached to this specification, that although I use two side rods spanning the cylinder, they virtually act as one rodin transmitting the power, for at one end they are connected rigidly to one pin, which has its bearing in the cross-head, and at the crank end they are connected rigidly to one box, this box being the full length of the crank-pin, so that when any lost motion by wear is taken up it is taken up the whole length of the bearin It will be noticed that the distance from the center of the shaft to the crank end of the cylinder is such as to allow the crank-pin and its box just room enough to properly clear. By this means the shaft pillow-blocks can be made very stiff and rigidly attached to the cylinder.

At the same timea connecting-rod is obtained of a length of eight times the crank.

In this engine a bed-plate or frame is entirely dispensed with. Where an air compressor or pump is driven directly by the piston-rod of this engine the crank and shaft may be placed at the end of either cylinder, as required. I attain these objects by the mechanism illustrated in the accompanying drawings, in which Figure 1 representsa side elevation of the engine. Fig. 2 is a section taken through the pillow-block in the line a a, also showing crankshaft. Fig. 3 is a plan of Fig. 1, showing a section through cylinder and pillow-block.

. A is the steam-cylinder; B, cross-head guide and distance-piececonnecting steam-cylinder A and air or water cylinder 0. D is a crosshead pin attached rigidly to side bars I I of connecting-rod. E is a single crank-pin box, with its cap attached to crank-pin end of conmeeting-rod; F F, cheeks or throws of crank,

made wide enough to allow piston G to pass between them when it is necessary to remove it from the cylinder or to examine it. J is the crank-pin. H is the eccentric-rod.

Similar letters refer to similar parts in the different views. v

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a back-acting engine having only a single crank-pin attached to two throws or cheeks, which are a suflicient distance apart to permit the piston and its rod to pass between them when it is necessary to remove them from the cy1inder,a connectin g-rod formed of two bars, attached rigidly at one end to a single journal-pin for the cross-head and at the opposite end to a single crank-pin box, construeted substantially as described, and for the purpose as herein set forth.

2. The combination of a connecting rod formed of two bars, which are rigidly attach ed to a single cross-head pin at one end and to a single crank-pin box at the other end, with a crank so arranged as to permit the piston and its rod to pass between the crank-cheeks when it is necessary'to remove it from the cylinder, constructed and arranged substantially as and for the purpose herein set forth.

. JOHN FISH.

Witnesses:

FRANK SAUNDERS, JOHN PRESTON. 

